Technical Field
The present disclosure relates to a semiconductor device and a semiconductor device manufacturing method.
Related Art
Semiconductor devices provided with a fuse element are commonly known. In these semiconductor devices, a protective film covers a region that includes a fuse element. It is difficult to penetrate the protective film and blow the fuse element from above the protective film. Accordingly, fuse windows are formed above the fuse element in these semiconductor devices.
In the example of a conventional semiconductor device 100 illustrated in FIGS. 13A and 13B, a rectangular shaped fuse window 120 is formed above a fuse element 114C. A silicon oxide film 116 and a silicon nitride film 118, serving as protective films, are stacked above a metal layer 114.
In the state illustrated in FIGS. 13A and 13B, current I flows from a metal layer 114A to a metal layer 114B due to the fuse element 114C not being blown.
When the fuse element 114C is to be blown, a laser or the like may be employed to blow the fuse element 114C inside the fuse window 120.
Japanese Patent Application Laid-Open (JP-A) No. H06-104338 describes technology in which a projection portion (a protrusion) that projects outward is provided inside a fuse window, and the projection portion is employed to position a laser beam that blows a fuse element.
In the conventional semiconductor device 100 illustrated in FIGS. 13A and 13B, sublimate generated when the fuse element 114C is blown adheres as deposit 115 to the inside of sidewalls of the fuse window 120, as illustrated in FIGS. 14A and 14B. In the conventional semiconductor device 100 illustrated in FIGS. 14A and 14B, a current path (what is known as a leak path) through which current I flows is formed by the deposit 115 due to the deposit 115 adhering to the entirety of the inside of the sidewalls of the fuse window 120.
There is accordingly an issue in that sometimes, even though the fuse element 114C has been blown, electrical continuity is produced between the metal layer 114A and the metal layer 114B, and shorting occurs.
Even if, for example, the technology described in JP-A H06-104338 were applied to address the above issue, the projection portion in the technology described in JP-A H06-104338 is provided for a different purpose. The shape of the projection portion would have to be made larger in order to be employed for positioning a laser beam, and accordingly the shape of the fuse window would also be made larger. Moreover, the technology of H06-104338 only describes using a projection as a positioner for a laser beam, and is insufficient to resolve the above issue.